The invention relates to a device for adjustment of the viewfinder eyepiece of a camera.
Devices which displace the eyepiece along its optical axis are necessary in order to be able to compensate for the defective vision of the camera user. This vision compensation is known as a diopter correction.
German Utility Model No. 1,830,283, discloses a direct-vision viewfinder for photographic cameras in which the diopter correction can be carried out on the eyepiece by means of a worm gear.
Furthermore, a diopter adjustment device for single-lens reflex cameras with an interchangeable viewfinder is described in German Offenlegungsschrift No. 2,824,334. The adjustment device has an eyepiece holder for securing the eyepiece that is arranged in the viewfinder so that the eyepiece holder can slide along the optical axis of the eyepiece. Additionally, the drive device that displaces the eyepiece holder from the outside of the camera is covered when the viewfinder is attached to the camera.
The disadvantage of both the direct vision viewfinder and the single-lens reflex camera devices is, however, that the diopter correction, once set, cannot be fixed or secured and the adjustment setting cannot be reproduced with certainty.
German Utility Model No. 1,994,235, discloses a viewfinder eyepiece which is mounted so that the viewfinder can be displaced axially by the effect of a spring. The spring forces the eyepiece out of the camera body to an end position which is limited by a stop. The eyepiece can be moved against the spring force into a position which compensates for the defective vision of the user by pressing a button. The eyepiece can be fixed in this position by means of a catch device.
The disadvantage of this device includes the fact that the adjustment setting cannot be reproduced with certainty. This device also lacks adequate adjustment accuracy.